JP2006100134A - Manufacturing method of color conversion filter substrate and organic el element using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a color conversion filter substrate including a method for forming a protective layer disposed without damage to the function of fluorescent pigments used for color conversion filter layers. <P>SOLUTION: The manufacturing method of the color conversion filter substrate comprises at least steps of forming a color conversion filter layer on a transparent support substrate, and forming the protective layer on the color conversion filter layer and the transparent support substrate. The step of forming the protective layer is one in which after the protective layer is film-formed on the color conversion filter, the protective layer is heat-cured while the transparent support substrate is cooled. A manufacturing method of a color organic EL element including the manufacturing method of the color conversion filter substrate is further provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a color conversion filter substrate having high definition and excellent environmental resistance and productivity, and a color organic EL device including the color conversion filter substrate. In particular, the present invention relates to a color conversion filter substrate that can be used for display of an image sensor, a personal computer, a word processor, a television, a facsimile, an audio, a video, a car navigation, an electric desk calculator, a telephone, a portable terminal, and industrial instruments. The present invention relates to a color organic EL device comprising the color conversion filter substrate. The color organic EL device of the present invention can be used for the above-mentioned device using the color conversion method including the color conversion filter substrate, and can perform color display.

Tang et al. Reported a stacked EL device capable of obtaining a high luminance of 1000 cd / m ² or more at an applied voltage of 10 V (Non-patent Document 1). Since then, organic EL devices have been actively researched for practical use. Has been done. The organic EL element is a thin film self-luminous element, and has characteristics not found in other systems such as a low driving voltage, high resolution, and high visual field, and is expected to be applied to a flat panel display.

  When considering the application of organic EL elements to displays, it is essential to display multiple colors in order to expand their uses.

  As a method of multicolor display, there are a method of sequentially patterning three primary color EL elements and arranging them on a plane, and a method of installing a color filter of three primary colors (red, green, blue) on a white light emitting element.

  However, the patterning of the EL elements of the three primary colors is very complicated, and the yield is poor and mass production is not easy. On the other hand, in the color filter system, a white light emitting element that can stably obtain sufficient luminance has not been obtained yet, and it is still difficult to put it into practical use.

  Therefore, in recent years, a color conversion method has been developed in which a fluorescent material that absorbs light in the light emitting region of the organic EL element and emits fluorescence in the visible light region is used as a filter (hereinafter referred to as “color conversion filter layer”) (Patent Literature). 1 and Patent Document 2). In this color conversion method, since the light emission color of the light emitting element is not limited to white, a light emitting element with higher luminance can be applied to the light source. In particular, in a color conversion method using a blue light emitting organic EL element, the conversion efficiency to a long wavelength is 60% or more.

  One of the points to be noted when manufacturing a color organic EL element such as a display by the color conversion method is the distance between the color conversion filter substrate and the organic EL element. As this distance increases, the light emission of adjacent pixels tends to leak, and the viewing angle characteristics deteriorate. Therefore, the shorter the distance between the color conversion filter substrate and the organic EL element, the better the viewing angle characteristics, and it is desirable to form the organic EL layer directly on the upper surface of the color conversion filter substrate. However, rhodamine-based, pyridine-based, oxazine-based, and coumarin-based pigments (such as Patent Documents 3 to 11) known as fluorescent pigments used in the color conversion layer of the color conversion filter substrate are ultraviolet light, heat, or organic solvents. It is known that the fluorescence wavelength is often changed or quenched due to the influence. Therefore, when a light emitting part including an organic EL layer is directly formed on the upper surface of the color conversion filter substrate, the color conversion filter is formed by plasma generated in the sputtering process of the transparent electrode, a peeling solution used for patterning the transparent electrode, or the like. The problem is that the layer easily loses its function.

  Furthermore, an important practical issue of the color organic EL element is that it has a fine color display function and has long-term stability including color reproducibility (see Non-Patent Document 2). However, the current-luminance characteristic of the color organic EL element is remarkably deteriorated by driving for a certain period.

  A typical cause of the deterioration of the light emission characteristics is the growth of dark spots. This dark spot is a light emitting defect point. When oxidation of the organic EL element proceeds during driving and storage of the organic EL element, the growth of dark spots proceeds, and the defect spreads over the entire light emitting surface.

  This dark spot is considered to be caused by the oxidation or aggregation of the material constituting the organic EL element due to oxygen or moisture. The growth of this dark spot proceeds during storage as well as during energization. For example, regarding the organic EL element, in particular, (1) it is accelerated by oxygen or moisture present around the element, (2) it is affected by oxygen or moisture present as an adsorbent in the organic laminated film, and (3) the element It is considered that it is also affected by moisture adsorbed on the parts at the time of manufacture or moisture intrusion during production.

  As described above, the generation of dark spots is considered to be caused by oxygen and water in the organic EL element. In addition, for example, in a color organic EL element including a color conversion filter substrate, When a color conversion filter layer in which a color conversion pigment is mixed in a resin is used, there are the following problems with respect to moisture and the like. That is, the color conversion filter layer cannot be dried at a temperature exceeding 200 ° C. due to the thermal stability of the dye to be mixed. Therefore, the moisture contained in the pigment or the like may remain mixed. In addition, in an organic EL element using a color conversion filter substrate, moisture may be mixed in the color conversion filter layer, which is a component of the color conversion filter substrate, in the pattern forming process when constructing the color conversion filter substrate. There is a possibility that the color conversion filter substrate is formed in a state where moisture is retained. Moisture retained in the color conversion filter layer reaches the light emitting portion of the organic EL element during storage or driving of the color organic EL element and promotes the growth of dark spots.

  In a color organic EL element using the above-described color conversion filter substrate, there is a method of disposing a protective layer having a gas barrier property as a method for dealing with moisture contained in the color conversion filter layer. As an example of forming a protective layer having gas barrier properties, for example, a protective layer is formed by disposing a planarizing layer made of a polymer material and an inorganic oxide or inorganic oxide layer (Patent Documents 5 and 5). Patent Document 12), forming a protective layer by laminating a thermosetting resin or ultraviolet curable resin and a barrier layer containing silicon oxide (Patent Document 13), and bonding a film with a hard coat layer with a binder Thus, forming a protective layer (Patent Document 14), forming a protective layer and a hard coat layer with a polymer material (Patent Document 15 and Patent Document 16), and the like are disclosed.

Patent Document 17 does not provide a protective layer having a high gas barrier property, but includes a substrate member, a transparent protective layer formed on the substrate member, and a conductive layer formed on the protective layer. It is disclosed that a transparent conductive film containing ultrafine particles is transferred onto a substrate. The object of the present invention is to fill the voids in the porous transparent substrate with a protective layer to improve the optical characteristics.
Japanese Patent Laid-Open No. 3-152897 JP-A-5-258860 JP-A-8-78158 JP-A-8-222369 JP-A-8-279394 JP-A-8-286033 JP-A-9-106888 Japanese Patent Laid-Open No. 9-208944 JP-A-9-245511 JP-A-9-330793 Japanese Patent Laid-Open No. 10-12379 Japanese Patent Laid-Open No. 11-26156 JP 2001-60495 A Japanese Patent Laid-Open No. 11-121164 JP 2000-182780 A Japanese Patent Laid-Open No. 11-219786 JP-A-5-325646 Japanese Patent Laid-Open No. 5-134112 JP-A-7-218717 JP-A-7-306311 JP-A-5-119306 JP-A-7-104114 JP 7-48424 A JP-A-6-300910 JP 7-128519 A JP-A-5-36475 Appl.Phys.Lett.51,913 (1987) Functional Materials, Vol. 18, No. 2, p. 96 Monthly Display 1997, Volume 3, Issue 7

  However, when forming a protective layer with the materials described in the above documents, it is necessary to expose these materials to ultraviolet irradiation or a high temperature of 200 ° C. or higher in order to cure these materials, and the color conversion filter layer also has such a high temperature. Will be exposed to. It has been reported that when cured at a high temperature of 200 ° C. or higher, the fluorescent dye contained in the color conversion layer in the color conversion filter layer is quenched by the influence of heat and the color conversion efficiency is lowered (Patent Document 5). . Therefore, it is very difficult to form a protective layer using the above materials without deteriorating the properties of the color conversion layer, and the protective layer having low degassing performance, gas barrier performance, and resistance to subsequent processes. It is difficult to form. Thus, the above materials are insufficient for use as a material for the protective layer of the color conversion filter layer. Moreover, the material of a protective layer is remarkably limited by the said situation.

  Therefore, it is desirable to develop a protective layer material that can be disposed without impairing the function of the fluorescent dye used in the color conversion filter layer, or to develop a protective layer formation process that can fully exhibit the performance of the material. It was.

  The present invention has been made in view of the above-described problems, and a method for producing a color conversion filter substrate including a method for forming a protective layer that can be disposed without impairing the function of the fluorescent dye used in the color conversion filter layer And it aims at providing the manufacturing method of the color organic EL element using the color conversion filter substrate manufactured by this manufacturing method.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors impair the function of the color conversion filter layer even when using a conventional protective layer material that requires curing at a temperature of 200 ° C. or higher. The present invention has been completed by finding a method for forming a protective layer that can withstand the film formation conditions when the layers of the organic EL element can be laminated on the upper surface of the protective layer, and can fully exhibit the performance of the protective layer. It came to do.

  That is, the first of the present invention relates to a method for manufacturing a color conversion filter substrate. This manufacturing method includes at least a step of forming a color conversion filter layer on a transparent support substrate and a step of forming a protection layer on the color conversion filter layer and the transparent support substrate, and forms the protection layer. The step is characterized in that after the protective layer is formed on the color conversion filter layer, the protective layer is heated and cured while cooling the transparent support substrate.

  2nd of this invention is related with the manufacturing method of a color organic EL element. The first embodiment of the manufacturing method includes at least a step of forming a color conversion filter layer on a transparent support substrate, and a step of forming a protective layer on the color conversion filter layer and the transparent support substrate, And a step of sequentially laminating a transparent electrode, an organic EL layer, and a second electrode (light emitting portion of the organic EL element) on the color conversion filter substrate, and the step of forming the protective layer forms a protective layer Then, the protective layer is heated and cured while cooling the transparent support substrate.

  Another embodiment of the method for producing a color organic EL device of the present invention includes a step of forming a color conversion filter layer on a transparent support substrate and a step of forming a transparent protective layer on the color conversion filter layer. A step of forming an organic EL element comprising at least a step of forming a conversion filter substrate, a step of sequentially laminating a first electrode, an organic EL layer and a second electrode on a support substrate; and the color conversion filter substrate and the organic And a step of forming the protective layer, wherein after forming the protective layer, the protective layer is heated and cured while cooling the transparent support substrate.

  In the production method of the present invention, means for heat-curing the protective layer includes bringing the film surface of the protective layer close to a hot plate, irradiating an infrared lamp from the film surface of the protective layer, and the like. In the manufacturing method of the present invention, the means for cooling the transparent support substrate includes bringing the support substrate into close contact with the cooling plate, blowing cool air onto the support substrate, and the like.

  According to the present invention, the production method of the present invention can cure the protective layer at a sufficient temperature without damaging the color conversion filter layer. Therefore, the color conversion filter substrate formed by the method of the present invention can be a substrate in which dark spots are hardly generated. Further, by using this substrate, it is possible to provide a color organic EL element such as a color conversion type color organic EL display capable of maintaining stable light emission characteristics over a long period of time.

  The present invention will be described below. In the following description, the present invention will be described with reference to the drawings as appropriate. However, these descriptions are merely examples, and the present invention is not limited thereto.

  First, an example of the structure of the color conversion filter substrate and the color organic EL element according to the manufacturing method of the present invention will be described with reference to FIG. FIG. 1A is a schematic cross-sectional view of a color conversion filter substrate, and FIGS. 1B and 1C are schematic cross-sectional views of a color organic EL element.

  The color conversion filter substrate 10 is formed of a black matrix 108, red, green, and blue on a support substrate 118 that is transparent and stable (does not generate a component that degrades the phosphor material or the organic EL element in a range of room temperature to 150 ° C.). A color conversion filter layer 110 (a red conversion filter layer, a green conversion filter layer, and a blue conversion filter layer) made of a dye or a pigment is formed. Further, the color conversion filter substrate includes a protective layer 119. In FIG. 1A, the protective layer 119 is shown as having two layers (114b and 128) of two different materials.

  The color conversion filter substrate of the present invention has a protective layer 119, and this protective layer has a smooth surface opposite to the transparent support substrate side, and diffusion of moisture contained in the color conversion filter layer. It is characterized by having a high gas barrier property and sufficient sealing property so as not to occur. Further, it is important that the surface of the protective layer does not have pinholes or the like that allow moisture from the color conversion filter to flow out. Furthermore, when a transparent electrode, an organic EL layer, a cathode, or the like is laminated on the protective layer, it is also necessary not to cause defects such as moisture paths in these layers. For this purpose, the protective layer is sufficient. Is required to be flat.

  Next, the color organic EL element according to the production method of the present invention will be described. FIG. 1B is a schematic cross-sectional view showing a first embodiment of a color organic EL element (a laminated passive matrix color organic EL element). FIG. 1C is a schematic cross-sectional view showing a second embodiment of a color organic EL display (a color organic EL element of a bonded active matrix type (hereinafter also referred to as TFT type)).

  The first embodiment of the color organic EL element is a so-called bottom emission type passive matrix color organic EL element 20 shown in FIG. As shown in FIG. 1B, the color organic EL element is a passive matrix organic EL element in which an organic EL element is directly laminated on the color conversion filter substrate.

  This type of color organic EL element has a first electrode 104 on the protective layer 119 of the color conversion filter substrate, an organic EL layer 116, a second electrode 106, and a sealing member 124 provided thereon. Further, in FIG. 1B, a color organic EL element is shown as one pixel. However, a plurality of pixels may be included. In this case, in order to drive this in a passive matrix system, the first electrode and the second electrode Are formed in a line pattern, and the line pattern of the first electrode and the line pattern of the second electrode can extend in directions orthogonal to each other.

  As described above, the color organic EL device of the present embodiment is obtained by providing the black matrix 108, the color conversion filter layer 110, and the protective layer 119 on the transparent substrate 118.

  A second embodiment of the color organic EL element is a so-called top emission type active matrix color organic EL element 30 shown in FIG. The color organic EL element 30 has a structure in which the above-described color conversion filter substrate and the organic EL element are bonded together.

  The organic EL element has a TFT 122, a planarization layer 112, a first electrode 104, an organic EL layer 116, and a second electrode 106 provided thereon on a support substrate 102. In the present invention, the organic EL element is preferably provided with a passivation layer 114a.

  As described above, the color conversion filter substrate is obtained by providing the black matrix 108, the color conversion filter layer 110, and the protective layer 119 on the transparent substrate 118.

  In the color organic EL element, the color conversion filter substrate and the organic EL element are bonded together using the outer peripheral sealing layer 120, and a filler layer 126 is provided as necessary.

  In FIG. 1C, the color organic EL element is represented as one pixel. However, in the case of a plurality of pixels, the organic EL element is provided with a plurality of corresponding thin film transistors and a first electrode patterned to perform color conversion. A color conversion filter layer corresponding to this pattern may be provided on the filter substrate.

  Although not shown, the present invention is also directed to a bonded passive matrix color organic EL element (that is, the organic EL element portion in FIG. 1C is a passive drive system). . Such a color organic EL device includes a first electrode on a substrate, an organic EL layer provided on the first electrode, a second electrode, and a passivation layer provided on the second electrode as necessary. The EL element and the above-described color conversion filter substrate are bonded together as described above using an outer peripheral sealing layer or the like.

  The color organic EL device produced by the method of the present invention has the protective layer. This protective layer has a smooth surface on the side opposite to the transparent support substrate side, and has a high gas barrier property and sufficient hermeticity so that moisture contained in the color conversion filter does not diffuse. It is characterized by having.

  Next, a method for manufacturing a color conversion filter substrate of the present invention will be described with reference to the drawing (FIG. 2).

A) Step of forming a color conversion filter layer on a transparent substrate (see FIGS. 2A and 2B)
In the present invention, a matrix resin containing a dye or a pigment is applied onto a transparent substrate such as glass (Corning 1737 glass, which is non-alkali glass) manufactured by Corning, using a spin coating method or the like. A color conversion filter layer is formed by patterning using a method or the like.

  Below, the manufacturing method of this invention is demonstrated more concretely. In the present specification, the color conversion filter substrate includes at least a transparent substrate, a color conversion filter layer, and a protective layer, and optionally includes, for example, a black matrix. The color conversion filter layer is a general term for a color filter, a color conversion layer, and a laminate of a color filter and a color conversion layer. The color conversion layer emits light having different wavelengths by converting the wavelength of light emitted from the organic EL layer. The color filter transmits light in a specific wavelength range without performing wavelength distribution conversion.

  The method for producing a color conversion filter layer includes the following steps I) to II).

I) A step of forming a black matrix having openings corresponding to regions of red, green and blue color conversion filter layers on a transparent substrate (FIG. 2A).
In the present invention, for example, a black matrix material described below on a transparent substrate such as Corning glass (a non-alkaline glass, Corning 1737 glass) is formed by a spin coating method, a spray method, a dip method, or the like. After applying to the entire surface of the support substrate by a suitable application means, heating and drying, a pattern is formed by a photolithography method.

  In the manufacturing method of the present invention shown in FIG. 2, an example in which the black matrix 108 is provided has been shown. In the present invention, the black matrix 108 is an optional element, but it is preferable to provide this layer in order to provide contrast on the substrate. For example, the black matrix 108 can be provided in a region where the color conversion filter layer 110 is not provided between the color conversion filter layers 110 in FIG. The film thickness of the black matrix 108 is preferably 1 to 2 μm.

  A specific process for forming the black matrix 108 is as follows. First, on a transparent substrate such as a glass (Corning 1737 glass, which is a non-alkali glass) manufactured by Corning, for example, a black matrix material described below is applied to a dry process such as sputtering, CVD, or vacuum deposition. Alternatively, the entire surface of the substrate is coated by a coating means (wet process) such as a spin coating method, a spraying method, or a dip method. Next, if necessary (for example, in a wet process), after heat drying, a pattern is formed by a photolithographic method. That is, when a pattern is formed by etching using a metal material as a black matrix material, a positive resist is applied on the black matrix material by a spin coating method or the like, and an opening corresponding to the region of the color conversion filter layer is formed. A resist pattern is obtained by exposing and developing using a photomask to be formed. Next, the black matrix material is etched using the resist pattern as a mask, and the resist is stripped using a commercially available stripping solution or the like to form a black matrix having a desired pattern. In addition, when using a photosensitive resin black matrix material, after applying the resin material by a spin coat method or the like, it is exposed using a photomask in which openings corresponding to a desired black matrix pattern region are formed, developed, A black matrix is formed by post-baking. Note that it is preferable to use a black matrix having a light transmittance of 40% or less, preferably 30% or less, and most preferably 10% or less.

  The black matrix 108 is not particularly limited as long as it absorbs visible light well and does not adversely affect the light emitting portion and the color conversion filter layer. In the present invention, the black matrix is preferably formed by a black inorganic layer, a layer in which a black pigment or a black dye is dispersed in a resin, or the like. For example, as the black inorganic layer, a chromium film (chromium oxide / chromium laminated film) and the like can be given. Moreover, as a layer which disperse | distributed black pigment or black dye to resin, what disperse | distributed pigments or dyes, such as carbon black, phthalocyanine, and quinacridone, to resin, such as a polyimide, a color resist, etc. are mentioned, for example.

II) Step of sequentially forming red, green and blue color conversion filter layers in the openings of the black matrix (FIG. 2B)
In the present invention, a color conversion filter layer is formed by applying a matrix resin containing a dye or a pigment onto a transparent substrate on which a black matrix 108 is formed using a spin coating method or the like, and performing patterning using a photolithography method or the like. Form. For example, a matrix resin containing a fluorescent dye that emits blue fluorescence is applied onto the entire surface of a substrate on which a black matrix is formed by spin coating or the like, heated and dried, and then patterned by photolithography. This is performed also for the other color conversion filter layers to form a color conversion filter layer.

  Below, the specific manufacturing method of each color conversion filter layer is demonstrated. In the following description, each material will be described by taking as an example the case where an organic EL element that emits light in a blue to blue-green region is used as a light source, but the present invention is not limited to this.

[Preparation of blue filter layer]
A blue filter layer line pattern can be obtained by applying the material of the blue filter layer on a transparent support substrate by using a spin coating method or the like and performing patterning by a photolithography method or the like. That is, after a blue filter layer material is applied and dried, a resist is applied thereon by a coating means such as a spin coat method, a spray method, or a dip method to form a blue filter layer region. The resist pattern is obtained by exposing through light and developing. Next, the blue filter material having a desired pattern is formed by etching the blue filter material and stripping the resist. The above-mentioned line pattern varies depending on the desired color organic EL element, but for example, the line width can be 0.1 mm, the pitch is 0.11 mm, and the film thickness is 10 μm.

[Production of green conversion filter layer]
A fluorescent dye for green conversion is dissolved in a solvent, and a photopolymerizable resin is added thereto to obtain a solution of a curable resin composition. This solution is applied to a transparent support substrate on which a blue filter line pattern has already been formed using a spin coating method or the like, and patterning is performed by a photolithography method or the like, whereby the green conversion filter layer line is formed. A pattern can be obtained. That is, after the material for the green color conversion filter layer is applied and dried, a resist is applied thereon by a coating means such as a spin coat method, a spray method, or a dip method, which corresponds to the region of the green color conversion filter layer. A green conversion filter layer is formed by performing exposure and development and post-baking using a photomask having openings. The above-mentioned line pattern varies depending on the desired color organic EL element, but can be, for example, a line width of 0.1 mm, a pitch of 0.11 mm, and a film thickness of 10 μm.

[Production of red conversion filter layer]
A fluorescent dye for red conversion is dissolved in a solvent, and a photopolymerizable resin is added thereto to obtain a solution of a curable resin composition. This solution is applied to the transparent support substrate on which the line pattern of the blue filter layer and the green conversion filter layer is formed using a spin coating method, etc., and patterning is performed by a photolithography method or the like, thereby converting the red color. Obtain a filter layer. That is, after the material for the red color conversion filter layer is applied and dried, a resist is applied thereon by a coating means such as a spin coat method, a spray method, or a dip method, which corresponds to the region of the red color conversion filter layer. A red conversion filter layer is formed by performing exposure and development and post-baking using a photomask having openings. The above-mentioned line pattern varies depending on the desired color organic EL element, but can be, for example, a line width of 0.1 mm, a pitch of 0.11 mm, and a film thickness of 10 μm.

  In addition, in formation of each said filter layer, the drying after application | coating is performed at 60 to 100 degreeC, Preferably it is 80 degreeC. As other conditions, conventionally known conditions can be used, or those conditions can be easily derived by those skilled in the art. For example, in a blue filter, the prebaking temperature after spin coating is 80 ° C. for 15 minutes, and the drying temperature after exposure and development is, for example, 200 ° C. for 30 minutes. In the green conversion filter, for example, the prebaking temperature after spin coating is 80 ° C. for 15 minutes, and the drying temperature after exposure and development is 180 ° C. for 30 minutes. In the green conversion filter, for example, the pre-baking temperature after spin coating is 80 ° C. for 10 minutes, and the drying temperature after exposure and development is 180 ° C. for 30 minutes.

  In the present invention, the color conversion filter layer can be formed as a stripe pattern separated for each color, but it is also preferable to have a structure separated for each sub-pixel as well as for each color.

  In the present invention, each color conversion filter layer preferably has the same region as the opening of the black matrix, but may be a region larger than the opening of the black matrix.

  In the present invention, a color filter layer may be further provided in the color conversion layer. That is, when sufficient color purity cannot be obtained with only the green or red conversion filter layer, a color filter layer can be provided. The thickness of the color filter layer is preferably 1 to 1.5 μm. The color filter layer can be formed by the same method as the blue filter layer. As described above, the color conversion filter layer of the present invention is obtained.

Each element used for manufacturing the color conversion filter substrate will be described below.
1. Color conversion filter layer In this specification, the color conversion filter layer is a layer formed by containing an organic fluorescent dye described below in a matrix resin (referred to herein as a color conversion layer), and this color conversion. It means a layer including a color filter layer provided when sufficient color purity cannot be obtained by the layer alone. In the color conversion filter layer, the color filter layer is an optional component. In the present invention, when an organic EL element that emits light in a blue to blue-green region is used as a light source, only a blue filter can be used as a color conversion filter layer. Below, the material etc. which are used for a color conversion filter layer are demonstrated. In the following description, each material will be described by taking as an example a case where an organic EL element that emits light in a blue to blue-green color region is used as a light emitting source, but the present invention is not limited to this.

1) Organic fluorescent dye In the present invention, the organic fluorescent dye absorbs light in the near-ultraviolet region or visible region, particularly light in the blue or blue-green region emitted from the organic EL device, and has a wavelength different from that of the light emitting device. As long as it emits visible light, it is not particularly limited. In the present invention, at least one type of fluorescent dye that emits fluorescence in the red region is used, and it is preferable to combine with one or more fluorescent pigments that emit fluorescence in the green region. This is due to the following reason. It is easy to obtain an organic EL element that emits light in the blue to blue-green region. However, if the light is passed through a simple red filter and changed to light in the red region, the light in the red region is originally low. , It becomes very dark output light. Therefore, in order to obtain light in the red region having sufficient output, it is necessary to temporarily absorb the light from the organic EL element by the fluorescent dye and convert it into light in the red region.

  On the other hand, the light of the green region may be output by converting the light from the organic EL element into the light of the green region by another fluorescent dye, or the light emission of the organic EL element, similarly to the light of the red region. May sufficiently output light from the light emitting element through a green filter.

  For light in the blue region, light from the organic EL element can be output through a simple blue filter.

  Examples of fluorescent dyes that absorb blue to blue-green light emitted from an organic EL element and emit red light include the following organic fluorescent dyes. That is, rhodamine dyes such as rhodamine B, rhodamine 6G, rhodamine 3B, rhodamine 101, rhodamine 110, sulforhodamine, basic violet 11, basic red 2, etc., cyanine dye, 1-ethyl-2- [4- (p-dimethyl) Pyridine dyes such as aminophenyl) -13-butadienyl] -pyridium-perchlorate (pyridine 1) or oxazine dyes. Furthermore, various dyes (direct dyes, acid dyes, basic dyes, disperse dyes, etc.) can be used as long as they can emit desired fluorescence.

  Examples of fluorescent dyes that absorb blue to blue-green light emitted from organic EL elements and emit green fluorescent light include the following organic fluorescent dyes. That is, 3- (2-benzothiazolyl) -7-diethylaminocoumarin (coumarin 6), 3- (2'-benzoimidazolyl) -7-N, N-diethylaminocoumarin (coumarin 7), 3- (2'-N, N -Methylbenzimidazolyl) -7-N, N-diethylaminocoumarin (coumarin 30), 2,3,5,6-1H, 4H-tetrahydro-8-trifluoromethylquinolidine (9,9a, 1-gh) coumarin ( Coumarin dyes such as Coumarin 153), or Basic Yellow 51 which is a Coumarin dye, and Naphthalimide dyes such as Solvent Yellow 11 and Solvent Yellow 116. Furthermore, various dyes (direct dyes, acid dyes, basic dyes, disperse dyes, etc.) can be used as long as they can emit desired fluorescence.

  The organic fluorescent dye that can be used in the present invention includes polymethacrylate, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer resin, alkyd resin, aromatic sulfonamide resin, urea resin, melamine resin, benzoguanamine resin, and An organic fluorescent pigment may be obtained by kneading into a resin mixture or the like in advance to obtain a pigment. In addition, these organic fluorescent dyes and organic fluorescent pigments (in the present specification, the above two are collectively referred to as organic fluorescent dyes) may be used alone, or two or more of them may be used to adjust the hue of fluorescence. May be used in combination. The organic fluorescent dye used in the present invention is contained in an amount of 0.01 to 5% by weight, more preferably 0.1 to 2% by weight, based on the weight of the conversion filter layer, with respect to the color conversion filter layer. It is preferable. If the content of the organic fluorescent dye is less than 0.01% by weight, sufficient wavelength conversion may not be performed. If the content exceeds 5%, the color may be reduced due to effects such as concentration quenching. There may be a decrease in conversion efficiency.

  In the present invention, the color conversion filter layer can include the specific values shown above for the line width, pitch, film thickness, etc., but these values vary depending on the desired color organic EL element, and the values are particularly limited. Not. For example, the line width can be 0.06 mm to 0.1 mm, and the pitch can be 0.21 mm to 0.33 mm. The film thickness can be 5 μm or more, preferably 8 to 15 μm.

2) Matrix resin Next, the matrix resin used for a color conversion layer among the color conversion filter layers of this invention is demonstrated. The matrix resin is made of a photocurable resin or a photothermal combination type curable resin. This is subjected to light and / or heat treatment to generate radical species and ionic species to be polymerized or crosslinked, and to insolubilize the resin to form a color conversion layer.

  Photocurable or photothermal combination type curable resins include (1) acrylic polyfunctional monomers and oligomers having a plurality of acryloyl groups and methacryloyl groups, (2) polyvinyl cinnamate, (3) chain or cyclic olefins And (4) monomers having an epoxy group.

  These curable resins are used as, for example, the following compositions, and are coated on a substrate and then patterned. For example, the curable resin (1) is mixed with light or a thermal polymerization initiator, and after applying the composition, it is subjected to light or heat treatment to generate photoradicals or thermal radicals for polymerization. Further, the curable resin (2) is mixed with a sensitizer, applied with this composition, and then crosslinked by light or heat treatment. The curable resin (3) is mixed with bisazide, and after applying the composition, nitrene is generated by light or heat treatment to crosslink with the olefin. The curing agent (4) is mixed with a photoacid generator, and after applying this composition, an acid (cation) is generated and polymerized by light or heat treatment. In the present invention, the composition comprising the photocurable or photothermal combination curable resin (1) can be patterned with high definition, and is preferable in terms of reliability such as solvent resistance and heat resistance.

3) Substrate As a substrate that can be used in the present invention, an insulating substrate made of glass or plastic, or a substrate in which an insulating thin film is formed on a semiconductive or conductive substrate can be used. These parameters such as the film thickness are the same as the conventional values.

B) Step of forming protective layer (FIGS. 2 (c) to (e))
The protective layer 128 of the present invention is obtained by applying a resin component, which is a material for forming the protective layer, on the color conversion filter substrate, using a dry method (sputtering method, vapor deposition method, CVD method, etc.), wet method (spin coating). (FIG. 2 (c)), and baking is performed using appropriate heating means and cooling means (FIG. 2 (d)).

  In the step of forming the protective layer 128 of the present invention, when the protective layer containing the resin component is heated and cured, the heating means 202 is brought close to the surface of the protective layer so that heat is transferred from the protective layer side, and simultaneously cooling is performed. Cooling is performed from the transparent substrate side by means 204 (FIG. 2D).

  Specific heating means for the protective layer include, for example, a method in which a heated hot plate is brought close to the protective layer and heated by radiation and heat conduction by air, or a method in which an infrared lamp is irradiated from the film surface side of the protective layer. is there. In addition, as a cooling means for the support substrate, there are a method of bringing the support substrate into close contact with the cooling plate, a method of blowing cool air onto the support substrate, and the like. In this invention, it is preferable that heating temperature is 200 to 250 degreeC, and it is preferable that cooling temperature is 0 to -270 degreeC. Moreover, 10 minutes-60 minutes are suitable for hardening time.

  In the conventional method using a hot air circulating oven or the method of heating from the support substrate side using a hot plate, the color conversion filter layer is also heated at the same time when the protective layer is heated and exposed to a high temperature. However, in the method of the present invention, a temperature gradient can be formed in the film thickness direction, and the temperature increase of the color conversion filter layer can be suppressed even when the protective layer is heated to a high temperature.

  In the present invention, the protective layer can be formed as a plurality of layers made of different materials (see FIG. 2E). In this case, the second protective layer (114b) is formed on the protective layer formed by the above-described method. There is no restriction | limiting in particular as a formation method of this 2nd protective layer, When using an inorganic material, it can form by usual methods, such as a sputtering method, CVD method, a vacuum evaporation method, a dip method, a sol-gel method. Further, when a polymer material is used, the formation method is not particularly limited. For example, it can be formed by a conventional method such as a spin coating method.

  Next, features, materials, etc. of the protective layer will be described.

  The flat protective layer having gas barrier properties that can be used in the present invention has high transparency in the visible region (transmittance of 50% or more in the range of 400 to 700 nm), Tg of 100 ° C. or more, and surface hardness of pencil. It is a layer having a hardness of 2H or more.

The material that can be used for the protective layer of the present invention may be any material that can form a coating film on the substrate so as to have a flat surface and does not deteriorate the function of the color conversion filter layer. For example, an imide-modified silicone resin (Patent Documents 18 to 20, etc.) and an inorganic metal compound (TiO, Al ₂ O ₃ , SiO ₂ etc.) dispersed in an acrylic resin, a polyimide resin, a silicone resin, etc. (Patent Document 21) And Patent Document 22), epoxy-modified acrylate resin as ultraviolet curable resin (Patent Document 23), resin having reactive vinyl group of acrylate monomer / oligomer / polymer, resist resin (Patent Documents 5, 10, 24, 25) Etc.), materials that can use the sol-gel method of inorganic compounds (described in Non-Patent Document 3, Patent Document 5 and the like), photocurable resins such as fluorine-based resins (Patent Document 10 and Patent Document 26, and the like) and There is a thermosetting resin.

  The protective layer may be a single layer or a laminate in which a plurality of layers are laminated. Moreover, when it consists of multiple layers, each layer may be the same material or different materials, but in order to improve the barrier properties, it is preferable to use different materials.

In the formation of the above-mentioned laminated body protective film, it has electrical insulation, has barrier properties against gases, organic solvents, etc., and has high transparency in the visible range (transmittance of 50% or more in the range of 400 to 700 μm). An inorganic material having a film hardness of preferably 2H or more can be used as the hardness that can withstand film formation of the anode. For example, inorganic oxides such as SiO _x , SiN _x , SiN _x O _y , AlO _x , TiO _x , TaO _x , ZnO _x , inorganic nitride, and the like can be used. These materials are suitable for forming the protective layer of the present invention, and the layer can be formed without impairing the flatness of the surface of the protective layer.

  When this protective layer is applied to a color conversion type color organic EL element, there are important factors to be considered. That is, the factor is the influence that the film thickness of the protective layer has on display performance, particularly viewing angle characteristics. In the color organic EL element of the color conversion system of the present invention, the particularly important viewing angle characteristic is a change in color that occurs when the viewing angle with respect to the element is changed.

  If the protective layer is too thick, the optical path length until the light generated in the organic EL layer reaches the color conversion filter layer via the protective layer becomes long. As a result, when a color organic EL display constructed using a color organic EL element is viewed from an oblique direction, light leakage (optical crosstalk) to adjacent pixels of another color occurs. Considering the display performance of the display, it is required that the ratio of the light emission amounts of adjacent colors due to this optical crosstalk is sufficiently smaller than the light emission amount of the original color.

This requirement is replaced by limiting the relationship between the thickness of the protective layer and the minimum pixel width. According to the published technical report 2001-6083, the thickness t _{PL of the} protective layer is preferably in the range represented by 0 <t _PL <0.1 W (W is the minimum pixel width).

  The color conversion filter substrate can be manufactured as described above.

  Next, with reference to FIGS. 3-5, the manufacturing method of each color organic EL element is demonstrated concretely. In the following description, a method for forming a color organic EL element having a plurality of pixels will be described as an example. However, the present invention is not limited to this, and includes a method for manufacturing a color organic EL element having one pixel.

  The first embodiment of the present invention is a method for manufacturing a stacked organic color organic EL element of a passive drive system.

  A method for manufacturing a passive matrix type organic EL element will be described with reference to FIGS.

(I) Process of forming a color conversion filter substrate The method for manufacturing a color organic EL element of the first embodiment includes a process of forming a color conversion filter substrate. This step is as described in the first invention.

(Ii) Step of forming first electrode, organic EL layer and second electrode In this step, first, a transparent electrode 104 is formed on the upper surface of the protective layer 119 which forms the outermost layer of the color conversion filter substrate manufactured as described above. Is formed (FIG. 3A).

  Next, an organic EL layer 116 made of, for example, a hole injection layer, a hole transport layer, an organic light emitting layer, and an electron injection layer is formed on the substrate on which the transparent electrode is formed (FIG. 3B).

Thereafter, a second electrode (cathode) 106 is formed using a mask that can obtain a stripe pattern perpendicular to the anode line (FIG. 3C).
Below, each film-forming process is demonstrated concretely.

(A) Formation of the first electrode (FIG. 3A)
A first electrode is formed on the protective layer by sputtering, photolithography, or the like. In the present invention, for example, a first electrode (anode) 104 can be formed by forming a film on the entire surface of the first electrode and applying a resist agent thereon, followed by patterning by a photolithography method or the like. For example, when IZO is used as the first electrode, a photoresist material (for example, OFPR-800 (manufactured by Tokyo Ohka Kogyo Co., Ltd.)) is applied onto IZO by a spin coating method, and this is applied at 50 ° C. using a clean oven or a hot plate. After prebaking and exposing at ~ 150 ° C for 60 seconds to 240 seconds, development may be performed to form a pattern of the first electrode. The first electrode can then be formed by etching the IZO with a weakly acidic solution such as oxalic acid. In the present invention, an insulating film can be formed on the first electrode as necessary. The insulating film can be formed by an appropriate method known to those skilled in the art, such as a lift-off resist method.

(B) Formation of organic EL layer (FIG. 3B)
Next, the organic EL layer 116 is formed on the color conversion filter substrate on which the first electrode is formed. The organic EL layer may be formed sequentially using, for example, a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer, and an electron injection layer without breaking the vacuum using a resistance heating vapor deposition apparatus. The organic EL layer 116 is not limited to this configuration, and can take various forms as will be described later. In each form, each layer may be formed using a resistance heating vapor deposition apparatus or the like.

(C) Formation of the second electrode (FIG. 3C)
Next, the second electrode is formed on the organic EL layer.

  A sputtering method, an ion plating method, a vapor deposition method, or the like can be used for forming the second electrode. In the present invention, it is preferable to use a DC sputtering method.

  In these steps, the second electrode forms the second electrode (cathode) 108 in a pattern perpendicular to the line pattern of the first electrode, for example. Such pattern formation can be performed by a known procedure such as using a mask having a pattern perpendicular to the first electrode.

(D) Sealing process (FIG. 3D)
The organic light-emitting device obtained as described above is placed in a glove box (desirably both oxygen and moisture concentrations are 1 ppm or less) in a dry nitrogen atmosphere, and a color conversion filter substrate provided with a sealing member 124 and a light-emitting portion Is sealed using a UV curable adhesive. The bonding conditions are the same as before.

  Next, a manufacturing method of the second embodiment (TFT type color organic EL element) of the present invention will be described with reference to FIGS.

(1) Step of forming color conversion filter substrate The method of manufacturing the color organic EL element of the second embodiment includes a step of forming a color conversion filter substrate. This step is as described in the first invention.

(2) Manufacturing method of TFT type organic EL element This manufacturing method of the organic EL element includes the following steps (A) to (D) (FIGS. 4A to 4D).

(A) Formation of TFT and planarization layer (FIG. 4A)
A TFT 122 and a planarization layer 112 are formed on the supporting substrate 102.

  The formation of the TFT and the planarization layer can be manufactured using means known in the art. That is, the plurality of TFTs 122 and the planarization layer 112 may be formed over the supporting substrate 102 by appropriately combining a coating method including a sputtering method, an evaporation method, a spin coating method, and the like, a photolithography method, and the like.

Each component will be described below.
(TFT (122))
The TFTs are arranged in a matrix on the support substrate 102, and a source electrode or a drain electrode is connected to the first electrode 104 corresponding to each pixel. Preferably, the TFT is a bottom gate type in which a gate electrode is provided under a gate insulating film, and has a structure using a polycrystalline silicon film as an active layer.

  The wiring portion for the drain electrode and the gate electrode of the TFT, and the structure of the TFT itself can be created by a method known in the art so as to achieve the desired withstand voltage, off-current characteristics, and on-current characteristics. it can. In addition, in the organic EL display of the present invention using the top emission method, since light does not pass through the TFT portion, it is not necessary to reduce the TFT in order to increase the aperture ratio, and the degree of freedom in designing the TFT can be increased. Therefore, it is advantageous to achieve the above characteristics.

(Planarization layer (112))
In the case of performing active matrix driving, a planarization layer is preferably formed on the TFT 122. The planarization layer is provided in a portion other than a portion necessary for the connection between the source electrode or drain electrode of the TFT 122 and the first electrode 104 and other circuits, and the substrate surface is planarized to form a high-definition pattern of the subsequent layer. make it easier. The planarization layer can be formed of any material known in the art. Preferably, it is formed from inorganic oxide or nitride, polyimide or acrylic resin.

(Support substrate)
As the supporting substrate 102, an insulating substrate made of glass, plastic, or the like, or a substrate in which an insulating thin film is formed over a semiconductive or conductive substrate can be used. Alternatively, a flexible film formed from polyolefin, acrylic resin, polyester resin, polyimide resin, or the like may be used as the support substrate 102.

  Parameters such as the thickness of the support substrate are conventional and can be appropriately selected by those skilled in the art.

  In the present invention, the support substrate 102 may be composed of at least a substrate and a reflective film described below. As the substrate, the above materials can be used as they are.

(Reflective film)
In the present invention, among the light emitted from the light emitting unit, the light traveling toward the first electrode side is efficiently reflected to the second electrode side by providing a reflective film. The reflective film that can be used in the present invention is not particularly limited as long as the light from the organic EL layer can be efficiently reflected to the second electrode side. For example, those made of a metal or an alloy that reflects light can be mentioned. The reflective film provided on the transparent substrate is preferably an amorphous film having excellent flatness because it also serves as a base layer for the organic EL layer. Suitable metals and alloys for forming the amorphous film include CrB, CrP, or NiP.

  The reflective film can be provided on the upper surface or the back surface (back surface) of a support substrate such as glass or plastic. Moreover, you may provide the reflective film patterned according to the shape of the 1st electrode on the support substrate.

  Furthermore, instead of the support substrate, a substrate made of a metal or alloy that reflects light may be used via an insulating layer, so that the substrate and the reflection film may be used together. Parameters such as the thickness of the reflective film are conventional and can be appropriately selected by those skilled in the art. Note that when a conductive metal is used as the reflective film, an insulating thin film is formed on the reflective film. As the material of the insulating thin film, the above-described passivation layer and planarization layer inorganic oxide film, inorganic nitride film, organic material, and the like can be used.

(Insulating film)
In the organic EL device of the present invention, an insulating film (not shown) can be disposed on a portion of the support substrate where the first electrode is not provided. As a material for the insulating film, any material may be used as long as it has sufficient insulation resistance against the driving voltage of the light emitting portion and does not adversely affect the light emitting portion. For example, it is preferable to use an inorganic oxide film or an inorganic nitride film. Examples of such an inorganic oxide film or inorganic nitride film include silicon nitride, titanium oxide, tantalum oxide, and aluminum nitride.

  Parameters such as the thickness of the insulating film are conventional and can be appropriately selected by those skilled in the art. For example, the film thickness is 200 to 400 nm, preferably 250 to 350 nm.

(B) Formation of the first electrode (FIG. 4B)
Next, a first electrode is formed. The first electrode may be formed on the planarizing layer by sputtering, photolithography, or the like. In the present invention, the method described in the formation of the first electrode can be applied. That is, the first electrode may be formed on the planarizing layer by sputtering, photolithography, or the like. In the present invention, for example, the first electrode 104 can be formed by depositing the entire surface of the first electrode, applying a resist agent thereon, and then performing patterning by a photolithography method or the like.

(C) Formation of organic EL layer (FIG. 4C)
Next, the organic EL layer 116 is formed on the support substrate on which the TFT, the planarization layer, and the first electrode are formed. The formation of the organic EL layer is as described above.

(D) Formation of second electrode and optional layer (FIG. 4 (d))
(Second electrode (106))
Next, a second electrode is formed on the organic EL layer.

  In the case of a TFT type color organic EL display, a second electrode is formed on the entire surface of the organic EL layer.

  A sputtering method, an ion plating method, a vapor deposition method, or the like can be used for forming the second electrode. In the present invention, it is preferable to use a DC sputtering method.

(Passivation layer (114a))
Next, it is preferable to form a passivation layer on the second electrode side as necessary. The method for forming the passivation layer is not particularly limited, and when an inorganic material is used, it can be formed by a conventional method such as a sputtering method, a CVD method, a vacuum deposition method, a dip method, or a sol-gel method. Further, when a polymer material is used, the formation method is not particularly limited. For example, it can be formed by a conventional method such as a dry method (sputtering method, vapor deposition method, CVD method, etc.) or a wet method (spin coating method, roll coating method, casting method, etc.).

  The above-described passivation layer may be a single layer or a stack of a plurality of layers. The thickness of the passivation layer (the total thickness in the case of a laminate of a plurality of layers) is preferably 0.1 to 10 μm.

(3) Sealing process The sealing process is a process of bonding the obtained organic EL element and the color conversion filter substrate together.
Specifically, the TFT organic EL element and the color conversion filter substrate formed as described above are placed in a dry nitrogen atmosphere (preferably, both oxygen and moisture concentrations are 1 ppm or less). And an ultraviolet curable adhesive is apply | coated to an outer peripheral part using a dispenser robot. Thereafter, the organic EL element and the color conversion filter substrate are brought into close contact with each other. Subsequently, the light emitting portion of the organic EL element and the color conversion filter layer are aligned. In the active matrix driving, the first electrode and the color conversion filter layer are aligned.

After that, the outer peripheral sealing layer 120 is formed by irradiating the aforementioned ultraviolet curable adhesive with ultraviolet rays to cure the adhesive. The ultraviolet irradiation is preferably performed, for example, at an illuminance of 100 mW / cm ² for 30 seconds.

  Although the manufacturing method of the present invention is not shown in the drawing, it is also applicable to a bonded passive matrix color organic EL element (that is, the organic EL element portion in FIG. 1C is a passive drive system). To do. According to the procedure described in the first embodiment, such a color organic EL element includes a first electrode, an organic EL layer provided thereon, a second electrode, and a second electrode directly on the substrate. An organic EL element is prepared by forming a passivation layer on the second electrode in accordance with the procedure described in the method for manufacturing the TFT type organic EL element, if necessary, and the above-described color conversion filter substrate Can be manufactured by bonding.

  Next, the components of the color organic EL element and the color organic EL element according to the present invention will be described in detail. In the present invention, the color conversion filter substrate is a constituent element. Therefore, the components and configuration of the color conversion filter substrate are as described above.

  The color organic EL element of the present invention includes the color conversion filter substrate of the first invention and an organic EL element. That is, light in the near ultraviolet to visible region, preferably light in the blue to blue-green region emitted from the organic EL element is incident on the color conversion filter layer, and the color conversion filter layer has a wavelength different from that of the incident light. This is a color organic EL element that outputs visible light.

  The organic EL element has a structure in which an organic light emitting layer is held between a pair of electrodes, and a hole injection layer or an electron injection layer is introduced as necessary. Specifically, the organic EL element can use the following layer structure.

(1) Anode / organic light emitting layer / cathode (2) Anode / hole injection layer / organic light emitting layer / cathode (3) Anode / organic light emitting layer / electron injection layer / cathode (4) Anode / hole injection layer / organic Light emitting layer / electron injection layer / cathode (5) Anode / hole injection layer / hole transport layer / organic light emitting layer / electron injection layer / cathode

  In the above layer structure, the anode is preferably transparent in the wavelength range of light emitted from the organic EL element. This is because light enters the color conversion filter substrate through the anode.

  In the above layer structure, at least one of the anode and the cathode is transparent in the wavelength range of light emitted from the organic EL layer. Light is emitted through this transparent electrode.

  In the present specification, the organic layer (organic light emitting layer, hole injection layer, hole transport layer, electron transport layer and / or electron injection layer) sandwiched between the first electrode and the second electrode is defined as an organic EL. This is called a layer. Moreover, in this specification, a 1st electrode, an organic electroluminescent layer, and a 2nd electrode are collectively called a light emission part. Further, in this specification, an element including at least a substrate, a light emitting portion, a planarization layer, and a protective layer is referred to as an organic EL element, and an element including a color conversion filter substrate and an organic EL element is referred to as a color organic EL element.

  Known materials are used as the material for each of the above layers. For example, as an organic light emitting layer, in order to obtain light emission from blue to blue-green, for example, a fluorescent whitening agent such as benzothiazole, benzimidazole, and benzoxazole, a metal chelated oxonium compound, a styrylbenzene compound, Aromatic dimethylidin compounds are preferably used. For the other layers, a conventionally used compound may be used.

(First electrode and second electrode)
The first electrode and the second electrode will be described. In the present invention, the following first electrode and second electrode can be used.

A) First electrode (104)
When the first electrode 104 is a TFT type, a patterned TFT is formed on a support substrate, a planarizing layer is formed thereon, and the first electrode is formed on the planarizing layer. The first electrode 104 and the TFT corresponding to each pixel are connected by a source electrode or a drain electrode. In the case of a passive matrix type, it is formed on the support substrate 102. The first electrode 104 can efficiently inject electrons or holes into the organic light emitting layer. The first electrode can be used as an anode or a cathode, but is preferably used as an anode in the present invention.

  When the first electrode is used as an anode, a material having a high work function is used in order to efficiently inject holes. In the organic EL device of the present invention that is a top emission method, the first electrode does not need to be transparent, but the first electrode can be formed using a conductive metal oxide such as ITO or IZO. Further, when a conductive metal oxide such as ITO is used, it is preferable to use a metal electrode (Al, Ag, Mo, W, etc.) having a high reflectance underneath. Since this metal electrode has a lower resistivity than the conductive metal oxide, it functions as an auxiliary electrode, and at the same time, the light emitted from the organic light emitting layer can be reflected to the color conversion filter substrate side to effectively use the light. It becomes possible. The first electrode can be a first electrode having a reflection function. Specifically, Ni or Cr having a high reflectivity is treated with ultraviolet rays instead of IZO or the like to make the work function equivalent to that of IZO or the like. In this way, holes can be injected and a predetermined reflective metal can be used as the anode.

  When the first electrode is used as a cathode, the top emission method uses a material having a low work function, such as an alkali metal such as lithium or sodium, an alkaline earth metal such as potassium, calcium, magnesium or strontium, or a fluoride thereof. An electron injecting metal or an alloy or compound with other metal is used. Similarly to the above, a metal electrode (Al, Ag, Mo, W, etc.) having a high reflectance may be used underneath, and in that case, low resistance and effective use of light emission of the organic light emitting layer by reflection are achieved. be able to.

B) Second electrode (108)
The second electrode can efficiently inject electrons or holes into the organic light emitting layer.

  In the case of the present invention which is a top emission method, the second electrode is required to be transparent in the emission wavelength region of the organic EL layer. For example, the second electrode preferably has a transmittance of 50% or more, preferably 90% or more with respect to light having a wavelength of 400 to 800 nm.

  When the second electrode is used as a cathode in the top emission method, it is required to be transparent in the wavelength range of light emitted from the organic light emitting layer. Therefore, in this case, it is preferable to use a transparent conductive material such as ITO or IZO. In addition, the material of the second electrode is required to have a small work function in order to inject electrons efficiently. In order to achieve both of the above-mentioned two characteristics of low work function and transparency, in the present invention, the second electrode is a layer composed of a transparent electrode layer and a material having a low work function (this is the same as that in the organic light emitting layer). It corresponds to an electron injection layer.). In general, since a material having a small work function has low transparency, this is effective. For example, materials such as alkali metals such as lithium and sodium, alkaline earth metals such as potassium, calcium, magnesium and strontium, or electron injecting metals such as fluorides thereof, alloys and compounds with other metals, etc. An extremely thin film (10 nm or less) can be used. A material such as Al or Mg / Ag can also be used.

  By using these materials having a low work function, efficient electron injection can be performed, and by using an ultrathin film, it is possible to minimize the decrease in transparency due to these materials. A transparent conductive film such as ITO or IZO is formed on the ultrathin film. The ultrathin film functions as an auxiliary electrode, and reduces the resistance value of the entire second electrode, making it possible to supply a sufficient current to the organic light emitting layer.

  When the second electrode is used as the anode, it is necessary to use a material having a large work function in order to increase the hole injection efficiency. In the case of the top emission method, it is necessary to use a highly transparent material in order for light emitted from the organic light emitting layer to pass through the second electrode. Therefore, in this case, it is preferable to use a transparent conductive material such as ITO or IZO.

(Passivation layer (114a))
The passivation layer is effective for preventing the permeation of oxygen, low molecular components and moisture from the external environment, and preventing the functional degradation of the light emitting part of the organic EL element due to them. The passivation layer is an optional layer, but is preferably provided for the above purpose. The passivation layer is preferably transparent in the light emission wavelength region in order to transmit the light emitted from the organic EL layer to the outside.

In order to satisfy these requirements, the passivation layer has high transparency in the visible region (transmittance of 50% or more in the range of 400 to 800 nm), electrical insulation, and barrier property against moisture, oxygen and low molecular components. Preferably, it is formed with the material which has the film hardness of 2H or more of pencil hardness. For example, materials such as inorganic oxides and inorganic nitrides such as SiO _x , SiN _x , SiN _x O _y , AlO _x , TiO _x , TaO _x , and ZnO _x can be used.

In addition, various polymer materials can be used for the passivation layer. Imide-modified silicone resins (Patent Documents 18 to 20), etc., materials in which inorganic metal compounds (TiO, Al ₂ O ₃ , SiO _2, etc.) are dispersed in acrylic, polyimide, silicone resins, etc. (Patent Documents 21 and 22), etc. Resin having a reactive vinyl group of acrylate monomer / oligomer / polymer, resist resin (Patent Documents 5, 10, 24, 25), etc., fluorinated resin (Patent Documents 10, 26), etc., or high thermal conductivity Examples thereof include a photocurable resin such as an epoxy resin having a mesogenic structure and / or a thermosetting resin.

Hereinafter, the present invention will be described in more detail with reference to examples.
First, an example in which the manufacturing method of the present invention is applied to an organic EL element in which an organic EL element is stacked on a color conversion filter substrate will be described. In the following embodiments, description will be made with reference to the drawings and reference numerals as appropriate (in the drawings, the blue, green, and red color conversion filter layers in the drawings are collectively shown as reference numeral 110. In the description, for convenience, the blue filter is described as 110B, the green conversion filter layer is described as 110G, and the red conversion filter layer is described as 110R).

Example 1
[1. Production of blue filter]
A blue filter material (manufactured by Fuji Film Arch: Color Mosaic CB-7001) is applied on a glass (Corning 1737 glass which is non-alkali glass) by Corning as a transparent support substrate 118 using a spin coating method. Patterning was performed by a photolithography method to obtain a line pattern of a blue filter 110B having a line width of 0.1 mm, a pitch of 0.33 mm, and a film thickness of 10 μm.

[2. Preparation of green conversion filter]
Coumarin 6 (0.7 parts by weight) as a fluorescent dye was dissolved in 120 parts by weight of propylene glycol monomethyl ether acetate (PGMEA) as a solvent. 100 parts by weight of a photopolymerizable resin “VPA100 / P5” (trade name, Nippon Steel Chemical Co., Ltd.) was added and dissolved to obtain a coating solution. This coating solution is applied to a transparent support substrate 118 on which a blue filter line pattern has been formed, using a spin coating method, followed by patterning using a photolithography method, and the line width of the green conversion filter 110G. A line pattern having a thickness of 0.1 mm, a pitch of 0.33 mm, and a film thickness of 10 μm was obtained.

[3. Preparation of red conversion filter layer]
Coumarin 6 (0.6 parts by weight), rhodamine 6G (0.3 parts by weight) and basic violet 11 (0.3 parts by weight) are dissolved in 120 parts by weight of propylene glycol monomethyl ether acetate (PGMEA) as a solvent. It was. 100 parts by weight of a photopolymerizable resin “VPA100 / P5” (trade name, Nippon Steel Chemical Co., Ltd.) was added and dissolved to obtain a coating solution. This coating solution is applied onto a transparent support substrate 118 on which a line pattern of a blue filter and a green conversion filter has been formed by using a spin coating method, and patterning is performed by a photolithography method, so that a red conversion filter is obtained. A line pattern of 110R having a line width of 0.1 mm, a pitch of 0.33 mm, and a film thickness of 10 μm was obtained.

[4. Preparation of protective layer]
As the protective layer 128, an acrylic transparent resin (NN810: manufactured by JSR Corporation) is applied to the transparent substrate 118 on which the line pattern of the color conversion filter has been formed with a film thickness of 5 μm by spin coating, and then the color Patterning was performed by a photolithography method so as to cover only the conversion filter layer. The support substrate 118 on which the protective layer is patterned is brought into close contact with a cooling plate cooled with liquid nitrogen (−196 ° C.) in a dry nitrogen atmosphere, and the support substrate 118 is cooled and kept at 240 ° C. The plate was brought close to the film surface side of the support substrate 118 so that the distance from the support substrate 118 was 0.2 mm and held for 30 minutes to cure the protective layer 128.

  After curing, 300 nm of silicon oxide was deposited by sputtering to form the second protective layer 114b. The film thickness of the obtained protective layer (lamination) on the color conversion filter layer was 5.1 μm.

[5. Preparation of organic EL element]
Next, six layers of anode / hole injection layer / hole transport layer / organic light emitting layer / electron injection layer / cathode were formed on the color conversion filter substrate manufactured as described above.

  First, a transparent electrode (ITO) was formed on the entire upper surface of the protective layer (laminated body) 119 constituting the outermost layer of the filter portion by sputtering. After applying a photoresist “OFRP-800” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) on ITO, patterning is performed by a photolithography method, and a width of 0.094 mm and a gap of 0. An anode having a stripe pattern of 016 mm and a film thickness of 100 nm was obtained.

  Next, the substrate 1 on which the anode was formed was mounted in a resistance heating vapor deposition apparatus, and a hole injection layer, a hole transport layer, an organic light emitting layer, and an electron injection layer were sequentially formed without breaking the vacuum. Table 1 shows the structural formula of the material used for each layer.

During film formation, the internal pressure of the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa. As the hole injection layer, copper phthalocyanine (CuPc) was laminated to a thickness of 100 nm. As the hole transport layer, 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (α-NPD) was laminated to 20 nm. The organic light emitting layer was formed by laminating 30 nm of 4,4′-bis (2,2′-diphenylvinyl) biphenyl (DPVBi). The electron injection layer was formed by stacking 20 nm of tris (8-hydroxyquinoline) aluminum complex (Alq3).

  Thereafter, from a Mg / Ag (10: 1 weight ratio) layer having a thickness of 200 nm using a mask capable of obtaining a stripe pattern having a width of 0.30 mm and a gap of 0.03 mm perpendicular to the anode (ITO) line. Was formed without breaking the vacuum.

  The organic EL device thus obtained was sealed with a sealing glass 124 and a UV curable adhesive in a glove box under a dry nitrogen atmosphere (both oxygen and moisture concentrations were 10 ppm or less).

(Example 2)
[1. Creation of TFT type organic EL device]
A TFT was patterned on a glass substrate by a conventionally known method. Next, IZO, which is the first electrode, was deposited to a thickness of 100 nm by sputtering using Ar as a DC sputtering gas. Thereafter, αNPD having a thickness of 40 nm was stacked as a hole injection layer by an organic vapor deposition apparatus, aluminum chelate (Alq3) having a thickness of 60 nm was stacked as an organic light emitting layer, and Li having a thickness of 1 nm was stacked as an electron injection layer. Next, IZO which is a second transparent electrode was formed by DC sputtering. The film formation conditions for IZO were Ar for the sputtering gas and IZO for the target. Thereafter, a passivation layer was formed according to a conventional procedure so as to cover each formed layer.

[2. Production of color conversion filter substrate]
The color conversion filter substrate was manufactured in the same manner as in Example 1.

[3. Bonding process]
The organic EL element and the color conversion filter substrate formed as described above were bonded and sealed using a UV curable adhesive in a glove box under a dry nitrogen atmosphere (both oxygen and moisture concentrations were 1 ppm or less).

(Comparative Example 1)
When the protective layer 128 was heat-cured, a color organic EL device was produced in the same manner as in Example 1 except that the protective layer 128 was kept for 30 minutes in a temperature circulating clean oven at a set temperature of 200 ° C. The film thickness of the protective layer (lamination) of this example on the color conversion filter layer was adjusted to be substantially the same as in Example 1, and was 5.0 μm.

(Comparative Example 2)
When the protective layer 128 was heat-cured, a color organic EL device was produced in the same manner as in Example 1 except that the protective layer 128 was kept for 30 minutes in a temperature circulating clean oven at a set temperature of 180 ° C. The film thickness of the protective layer (lamination) of this example on the color conversion filter layer was adjusted to be substantially the same as in Example 1, and was 5.3 μm.

(Evaluation)
The organic EL display produced using the protective layer of the example and the comparative example was continuously driven for 500 hours under an acceleration condition at a driving atmosphere of 85 ° C., and then the ratio and luminance of the non-light emitting area in the display panel were measured. And compared with the initial non-light-emitting area and luminance. In addition, the chromaticity (CIE-x, CIE-y) at the initial red lighting was measured. The results are shown in Table 2.

  As a result of the measurement, compared with the example, the comparative example 1 has the same increase in the area of the non-light-emitting region due to the growth of the dark spot, but the color purity of the red color is deteriorated. This is because the dye in the red color conversion filter 2 has been thermally damaged and deactivated when the protective layer 128 is heated and cured. In Comparative Example 2, the red color purity was not bad, but the growth of dark spots was noticeable, and the luminance retention was lower than that of the Example. From these results, the effects of the examples were confirmed.

FIG. 1A is a schematic sectional view of a color conversion filter substrate of the present invention. 1B and 1C are schematic cross-sectional views of the color organic EL device of the present invention. It is the schematic which shows the process for manufacturing the color conversion filter board | substrate of this invention. It is the schematic which shows the process for manufacturing the color organic EL element of this invention. It is the schematic which shows the process for manufacturing the color organic EL element of this invention. It is the schematic which shows the process for manufacturing the color organic EL element of this invention.

Explanation of symbols

10, 20, 30 Color organic EL display 102 Support substrate 104 First electrode 106 Second electrode 108 Black matrix 110 Color conversion filter layer 112 Flattening layer 114a Passivation layer 114b Second protective layer 116 Organic light emitting layer 118 Transparent substrate 119 Protection Layer 120 peripheral sealing layer 122 TFT
124 Sealing member 126 Filler layer 128 First protective layer 202 Heating means 204 Cooling means

Claims (7)

A method for producing a color conversion filter substrate comprising at least a transparent support substrate, a single or plural kinds of color conversion filter layers, and a transparent protective layer covering the color conversion filter layer,
The production method comprises at least a step of forming a color conversion filter layer on a transparent support substrate, and a step of forming a protective layer on the color conversion filter layer and the transparent support substrate,
The step of forming the protective layer is a step of heat-curing the protective layer while cooling the transparent support substrate after forming the protective layer on the color conversion filter. Production method. Forming a color conversion filter substrate including a step of forming a color conversion filter layer on a transparent support substrate, and a step of forming a protective layer on the color conversion filter layer and the transparent support substrate; and the color conversion filter Comprising at least a step of sequentially laminating a transparent electrode, an organic EL layer and a second electrode on the substrate,
A method for producing a color organic EL device, wherein the step of forming the protective layer is a step of heating and curing the protective layer while cooling the transparent support substrate after the protective layer is formed.   A step of forming a color conversion filter layer on a transparent support substrate, a step of forming a color conversion filter substrate including a step of forming a transparent protective layer on the color conversion filter layer, a first electrode on the support substrate, A step of forming an organic EL element comprising at least a step of sequentially laminating an organic EL layer and a second electrode, and a step of bonding the color conversion filter substrate and the organic EL element to form the protective layer The manufacturing method of the color organic EL element characterized by the process to heat-harden a protective layer, cooling a transparent support substrate after forming the protective layer.   The protective layer on the color conversion filter layer formed on the transparent support substrate is heated and cured by bringing a hot plate close to the film surface of the protective layer. Manufacturing method of color organic EL element.   The protective layer on the color conversion filter layer formed on the transparent support substrate is heat-cured by irradiating an infrared lamp from the film surface of the protective layer. Of manufacturing a color organic EL element.   4. The color according to claim 2, wherein the support substrate is brought into close contact with the cooling plate and cooled during the heat curing of the protective layer on the color conversion filter layer formed on the transparent support substrate. 5. Manufacturing method of organic EL element.   4. The color organic EL according to claim 2, wherein during the heat curing of the protective layer on the color conversion filter layer formed on the transparent support substrate, the support substrate is blown with cold air to be cooled. 5. Device manufacturing method.

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